Pustule Formation by Lactobacilli on Fermented Vegetables

Authors

T.L. Thompson, University of Nebraska-LincolnFollow
W.E. Engelhard, University of Nebraska-Lincoln
Hilliard Pivnik, University of Nebraska-Lincoln

Date of this Version

May 1955

Comments

Published in Applied Environmental Microbiology, volume 3, number 5, 1955. Copyright © 1955 by the American Society for Microbiology. Used by permission.

Abstract

Genuine dill pickles are the product resulting from the fermentation, predominantly lactic, of cucumbers immersed in a brine containing 3 to 4 per cent salt. The brine also contains dill weed and may contain spices and garlic or extracts of their essential oils. Genuine dill tomatoes are manufactured from green tomatoes by a fermentation similar to that used for pickles (Fabian and Wadsworth, 1944).
Lactobacillus plantarum is commonly associated with the fermentation of pickles (Pederson, 1936), although other lactobacilli and some yeasts undoubtedly play a role. A survery of the literature failed to uncover any reports concerning the microbial flora of fermenting dill tomatoes. Pederson (1936), however, mentions that L. plantarum has been found in fermenting and spoiled tomato products.
The formation of white pustules on fermented olives has been investigated by Vaughn et al. (1953). These workers found that the pustules were actually massive, subepidermal growths of L. plantarum. They also noted, but did not investigate, the presence of such pustules on fermented Italian peppers and pickled green tomatoes.
We have noted the presence of white pustules on commercially packed dill tomatoes and pickles and on sweet pickles prepared from salt stock. This report deals with microbiological and histological studies of pustules on dill tomatoes and pickles.